The objective of this proposal is to perform prospective longitudinal neurobehavioral followup studies of children who sustained either accidental or non-accidental (e.g., physical abuse) traumatic brain injuries. To assess the influence of environmental factors on cognitive and behavioral outcomes, comparison groups of children who 1) sustained physical abuse with no brain injury and 2) normal controls will be evaluated. To complete the prospective longitudinal study design, we enrolled a total of 124 children 0-6 years of age who differed in terms of the presence/absence of TBI and the presence/absence of physical abuse: inflicted TBI (n=31), noninflicted TBI (n=3 0), inflicted injury not involving the brain (n= 18), and uninjured comparison children (n=42). The attrition rate for the sample was very low: 8.0 % from baseline to 3 months and an additional 7.0% from 3 to 12 months. For children with inflicted TBI and other inflicted injuries, the attrition rate was 10%, which is very favorable since over 75% of these children have been returned to parental or family custody following conservatorship by the county protective agency. Neuroiniaging studies yielded signs of pre-existing brain injury, including cerebral atrophy, subdural hygroma, and ex-vacuo ventriculomegaly, in 45% of children with inflicted TBI and in none of the children with noninflicted TBI. Subdural hematomas and seizures occurred significantly more often in children with inflicted TBI. Intraparenchymal hemorrhage, edema, skull fractures, and cephalohemiatomas were similar in both groups. Retinal hemorrhage was only identified in the inflicted TBI group. Glasgow Outcome Scale scores indicated a significantly less favorable outcome after inflicted than noninflicted TBI. Good recovery was present in more children with noninflicted TBI (55% versus 20%) while moderate disability was present in more children with inflicted TBI (65% versus 20%). Deficits in children with a moderate disability included hemiparesis, cognitive scores in the borderline range, and/or requiring more than 1 rehabilitation therapy or placement in a self-contained classroom (e.g., early childhood intervention). Severe disability, characterized by total dependence for daily care inappropriate for chronological age, severe motor deficits, or cognitive deficiency, occurred in 15% of the inflicted TBI group and in 20% of the noninflicted TBI group. Mental deficiency was present in 45% of the inflicted and 5% of the noninflicted TBI groups. Characteristic features of inflicted TBI included acute CT/MR1 findings of pre-existing brain injury, extraaxial hemorrhages, seizures, retinal hemorrhages, and significantly impaired cognitive function without prolonged impairment of consciousness. Predictors of mental and motor outcome were evaluated in 31 children with inflicted and 29 children with noninflicted TBI. Stepwise multiple regression evaluated the relationship of Glasgow Coma Scale scores, CT/MRI findings, age at injury, and presence of physical abuse to mental and motor indices at baseline and 1 year. The duration of impaired consciousness was also considered but was significantly correlated with GCS (p<.0001) and did not make a significant unique contribution to prediction models. Outcomes were most closely related to CT/MFJ findings; children with multiple lesions, particularly infarcts, had less favorable outcomes. Lower GCS scores and physical abuse also predicted lower cognitive scores. While baseline motor outcome was only related to CT/MRI findings, GCS scores were also significant predictors at 1 year. Medical variables accounted for 18 to 38 percent of variability in mental and motor outcomes.